Radio frequency (RF) emanations from computers and video displays have been previously identified as potentially compromising emanations. That is, at least certain RF emanations have been discovered to be indicative of the data being transmitted, processed, displayed or otherwise associated with the corresponding device. Steps have been taken to address these RF emanations in order to protect the corresponding data. This has typically involved the use of various types of shielding techniques.
Various types of what may be characterized as information processing devices exist, such as data communication equipment, data encryption devices, modems, routers, line drivers, data loggers, computers, various types of data storage devices, data input/output devices, and printer sharing devices. At least some of these information processing devices may emit compromising RF signals. Many of these types of devices also utilize at least one light source for purposes of displaying a state of a serial data stream that crosses an interface of the particular information processing device. In at least certain situations this light source is modulated in accordance with the data signal that is being received by and/or transmitted from the associated information processing device.